The carrier mobility modeling compiles the current transport properties and their dependence on relevant parameters, such as carrier temperatures, lattice temperatures, impurity concentrations, and driving electric fields. Similarly to the carrier effective masses a material composition dependent modeling concept is introduced. The concept uses different binary material values for the low field mobility depending on which of the valleys in k-space is the minimum valley. Thus, a more precise modeling especially of the materials AlGaAs and InAlAs as a function of material composition is possible in comparison with a simple second order interpolation.